Pulse controlled selector circuit



June 8, 1948. G|ANSANTE 2,442,872

PULSE CONTROLLED SELECTOR CIRCUIT Filed May 27, 1944 IN VEN T OR.

affornqy Patented June 1943 2,442,872 PULSE CONTROLLED SELECTOR CIRCUITDaniel Giansante, Buffalo, N.

Colonial Radio Y., assignor to Corporation, Buflalo, N. Y.

Application May 27, 1944, Serial No. 537,656 6 Claims. (Cl. 177-353)This invention relates to pulse controlled circuits, and moreparticularly to circuits in which the apparatus may be selectivelycontrolled either from a nearby point or remotely, to operate one of anumber of circuits as may be desired. It will be understood, however,that my invention is not limited thereto and that the circuit hereindisclosed may also operate as a counting circuit.

In apparatus of the class described there will be provided some form oftransmitter which will deliver a series of pulses varying in number, andeach number corresponding to a particular circuit to be energized, or aparticular operation to be performed.

In the circuit shown, by way of example, I have provided for selectiveresponse to 1, 2, 3, 4, or pulses. In this instance, the transmission of1, 2, 3, or 4 pulses closes circuits 1, 2, 3, or 4, as the case may be,and reception of 5 pulses clears the apps.- ratus; that is to say,restores it to initial condition. It will be understood, however, thatwithin the scope of my invention additional circuits may be utilizedresponsive to a larger number of pulses.

Also, it may be noted that two modes of action are possible with mycircuit. If the pulses have a time interval between them which is longerthan the time of closure of the relays controlled, then the operationwill be sequential; that is tosay, if one pulse is sent and then a timeinterval greater than that required for the relay to close is allowed toelapse before the second pulse is sent, the relay which is operated byone transmitted pulse will operate.

When the second pulse is sent, the relay operated by the first pulsewill open and the relay operated by 2 pulses will close unless a thirdpulse arrives before the relay has had time to operate. However, if thepulses follow each other at a. rate faster than that which permits therelays to close, then the circuit will respond to only the total numberof pulses received. For example, if 3 pulses are sent in rapidsuccession, only the circuit responsive to 3 pulses will close, thecircuits responsive to 1 and 2 pulses not being put into operation. Thusit will be seen that merely by varying the transmission rate of thepulses the apparatus will function as a sequential or stepby-stepcontrol or as an integral control.

The pulses may be transmitted in any desired manner, such as by radio ordirect wire, and a great variety of operations may thus be remotelycontrolled. As an example, tanks, boats, and airplanes may be socontrolled. The apparatus also lends itself to the control of industrialequipment, being adapted to counting. sorting, and packaging 2machinery; and many other applications will be apparent to those skilledin the art.

The control may be exercised by the use of direct current pulses, aswhen sent over wire lines, or as pulse modulated radio frequency wavesfrom low to extremely high frequencies. In the latter case, of course, asuitable form of radio receiver will be employed to convert the incomingradio waves to voltage pulses.

For the purposes of this disclosure a pulse, as the term is employedherein, means a unidirectional current or voltage which increases with arather steep wave front to some finite value, remains at or near thatvalue for a measurable time interval which may, however, be extremelyshort, even of the order of microseconds -or fractions of a microsecond,and then decreases to zero.

Among the objects of my invention may be mentioned the following:

To provide apparatus of the class described which will count the numberof pulses received and operate a particular circuit in response to sucha number of pulses.

To provide such apparatus which is positive and reliable in operation.

To provide such apparatus which will operate either as a sequential orstep-by-step control or as an integral control.

To provide such apparatus which will respond to pulses as short asfractions of a microsecond, sent at a rate of as high as one thousandper second.

Still other objects and advantages of my invention will be apparent fromthe specification.

In the drawing, the single figure of the drawing is a circuit diagram ofapparatus in accordance with my invention.

Referring more particularly to the drawing, the

controlled pulses are applied to the input terminal X. As stated, thesepulses may be received by wire line, or they may be derived from theoutput of any suitable radio receiver. In the embodiment illustrated Ihave provided 3 tubes, designated as I0, 20, and 30.

These tubes are preferably of the gas ionization type, such asthyratrons, and the circuit operation is such that in response to onepulse, only tube I0 is ionized to close No. 1 controlled circuit. Fortwo pulses, tube 20 is fired and tube It extinguished, to close No. 2controlled circuit. For three pulses tube 30 is fired and tubes Ill and20 are extinguished, thereby closing No. 3'

controlled circuit, for four pulses tubes Ill and 30 are fired to closeNo. 4 controlled circuit, and for live pulses tubes 20 and 30 are firedto clear the denser ll.

nected to the cathode.

are impressed between control grid and cathode of tube l throughresistance H, condenser l2, resistance i3, and condenser it, to ground.The intermediate point between condenser l2 and resistance l3 may beconnected to the grid I99 and cathode Inc may be connected to groundthrough resistances l5, l6, and I1, and through resistance intermediatepoint between resistances I5 and It may be connected to the intermediatepoint between resistor l3 and con- The screen grid ilsg may be con-Connected in the anode circuit I may provide relay l9 operating-armaturel9a, the armature being grounded. The armature lta is normally springbiased to back contact position against back contact l9b, and when thetube l9 fires, the armature is drawn to front contact position againstfront contact I8 The winding of relay l9 may be shunted by condenser I90in series with resistance 191'. The plate circuit may be connected tothe +B terminal through resistance back contact 40b, and armature 49a.The armature 40a is biased to back contact position and is closed at alltimes except in response to the clearing signal of 5' pulses.

Incoming pulses are likewise impressed upon the second tube 29, whichmay also be a thyratron type tube having cathode 200,, control grid 1299, screen grid 29cc, and anode a. The control grid 200 may beconnected to the input terminal K through condenser 22 and resistance2|. Cathode 20c may be connected to ground through resistances 24 and 25and to 3+ through resistances 8 and 9 and the contact of relay 49. Thescreen grid 2llsg may beconnected through resistance 26 to theintermediate point between resistances l8 and IT and also throughresistance 23 to ground through condenser I. The anode 20a may beconnected through the winding of relay 29 and through resistance 9 andthe contact of relay 0 to +3, and the winding 29 may be shunted byresistance 29r.

Incoming pulses are also impressed upon the input circuit of tube 39.This may likewise be a tube of the thyratron type having cathode 300,control grid 300, screen grid 30sg, and anode 39a. The control grid 39gmay be-connected to the" input terminal through resistance 3| andcondenser 32, and through resistance 33 to the negative end ofresistance 24, cathode 39c may be connected to ground through resistance35 and to +3 through resistance 36 and to screen grid 20sg throughresistance 34, the screen grid 30sg to cathode 20c and throughresistance 21 and condenser 28 to ground, also through resistances 8 and9 and the contacts of relay to to +3. Anodes 29a and 30:: maybeconnected together through resistance 31 and condenser 39.

When no impulses have been received, relays I9, 29, and 39 are open, andtheir armatures l9a, 29a, and 39a and 39a2 are all in back contactposition, so that control circuits 1, 2, 3, and 4' are all open. Theoperation of the apparatus will now be described.

With tubes of the type described, the point at which the tube willionize or fire is a function of thecontrol grid voltage, screen gridvoltage, and the anode voltage; the more negative the screen grid isplaced with respect to the cathode, the more positive the control gridwill have to be for the tube to fire. Under normal conditions tube IIhas a negative bias on its grid of approximateiy 6 volts, and the screengrid lllsg is at cathode potential. Therefore, if a pulse voltage of +12volts is applied between cathode Ito and control grid l9y, tube lilwillfire.

The same first pulse voltage is applied to the grids of tubes 29 and 39,but neither of these tubes will fire with such pulse voltage because thenormal voltage on the screen grids 293p and Meg is approximately -l2.Therefore, one pulse will fire tube it only. When this occurs, relayarmature I 9a isclosed to front contact l9], ground is applied througharmature 3911!, and back contact 39bl to control .circuit 1, theapplication of ground to this circuit causing its operation in anysuitable and well-known manner.

When the tube l0 fires, the space current through it greatly increases,as will be understood. This space current flowing through resistancesl5, I6, and il produces an I. R. drop, which makes the pointbetweenresistance It and resistance ll more positive with respect to groundand, therefore, reduces the anode-cathode voltage on tube l9 and reducesthe negative bias on the screen grid 29sg, preparing the tube 20 to fireon the next pulse. In the arrangement shown I prefer to chooseresistance ll of such value that while tube in is ionized the screengrid 29sg is at zero or cathode potential. The apparatus will remain inthis condition until the second pulse is received.

When the second pulse is received, the voltage impressed ,on controlgrid299 will nowbe sufficient to fire the tube 29, closing armature 290against its front contact 29 and applying ground to control circuit No.2 to cause operation of such circuit. At the same time the increase inplate current drawn by the tube 20 through resistance 9 reduces thevoltage between anode and cathode on tube Ill to such an extent thatthis tube now deionizes and armature l9a returns to back contact,removing the ground from control circuit 1 and interrupting itsoperation.

The flow of space current in tube 20 through resistance 25 makes theupper' end of this resistance more positive with respect to ground, andsince this point is connected to control grid 399 through resistance 33,this grid moves in a positive direction with respect to cathode 30c tosuch an extent that the third pulse, when it ar-' rives, will cause tube30 to fire.

' At this point'it will be noted that since space current is no longerflowing through tube 19, the screen grid 20sy of tube 29 has returned toits normal' negative condition, and when tube 39 fires, a negative pulseis applied to anode 29a of tube 20 through condenser 38 to resistor 31,this, of course, being due to the sharp decrease in potential of anode39g when the tube fires. This is suificient to extinguish tube 20, sincethe voltage between anode 29a and cathode 290 is zero volts or less,releasing armature 29a, which returns to back contact position, removingthe ground from control circuit No. 2, and putting this circuit out ofoperation.

At the same time armatures 39a! and 39112 of relay 39 are moved to frontcontact position putting ground on control circuit No. 3, througharmature l9a, back contact l9b, armature 3902, and front contact 3912.Control circuit lie. 4 is prepared by the closure of armature 39alagainst front contact 391i, but since this circuit is open at frontcontact isf, ground is not applied-to circuit 4. The apparatus is now ina condition in which tube 30 is ionized, tube III is prepared to fire,since tube 20 is out, but tube 20 has its screen grid biased negativelyso that it cannot fire on the next pulse.

The next or fourth pulse does not interfere with the operation of tube30, which remains in its ionized condition, but it does-cause tube ID tofire in exactly the same way as the first pulse did, thus closingarmature iSa against front contact l9! and applying ground to controlcircuit 4 through the prepared circuit as already described, andremoving the ground from control circuit 3, which is now open at theback contact lib. At the same time tube 20 is prepared to fire exactly.as it was forthe second pulse, by the removal of the negative bias fromthe screen grid 20sa-because of the I. R. drop developed in resistancel1.

When the fifth pulse occurs, tube 20 again fires exactly as .it did forthe second pulse, opening back contact 29b of relay 29, thereby openinga short-circuit around relay 40, which was previously maintained throughback contact 33122 and armature 39112, and back contact I 91)- thearmature l9a to ground, thence to relay 40. The relay 40 is thereuponenergized, opening the B supply circuit to all the tubes by movement ofarmature 40a away from back contact 40b. This opening of the B supplycircuit, of course, deionizes tubes I0, 20, and 30, and the apparatusreturns to initial condition.

The following comments may be helpful in understanding detailed pointsin connection with the operation. Relay coil i8 is shunted by condenserI80 to prevent any inductive surge which might cause faulty operation ofrelay l9, and resistance I91 is included to prevent any resonanceeflects. Resistance 291' is included to eliminate any resonant effects.Resistance 4| is included to prevent short-circuiting of the B supply.Relays IS, 29, and 39 are preferably 5 mil relays.

It will be noted also that tubes I0 and 20 are deionized through theapplication of voltages developed in the circuit, and do not require theinterruption of the B supply, but this is not the case of tube 30. Oncethis tube fires, it will remain in ionized condition until the B supplyis opened by relay 40. Tubes I 0 and 20 can never both be ionized at thesame time because th plate voltage supplied through R9 is not sufiicientto maintain both in ionized condition, although it will maintain eithertube [0 or tube 20.

It may now be seen that if the pulses are of such short duration andfollow each other so rapidly that relays I9, 29, and 39 do not have timeto operate, the apparatus will operate as an integral device; that is tosay, if 4 pulses are sent, control circuits Nos. 1, 2, and 3 will nothave time to be closed, and only the circuit 4 will be closed, while ifthe pulses are of sufflclent duration to fire the thyrarons' but followeach other at time intervals which permit relays I9, 29, and 39 toclose, the apparatus will operate in sequence; that is to say, controlcircuit 1 will be closed at the first pulse and opened at the secondpulse, 2 at the second pulse and opened at the third, 3 at the thirdpulse and opened at the fourth, and 4 at the fourth pulse and will beopened at the fifth.

Let us assume that the apparatus has registered three pulses; that is,control circuit No. 3 is closed and the clearing signal (five impulses)be now sent at a rate faster than the electromechanical relays canoperate. On the first imelectronic operation and 6 pulse or the clearingsignal, the tubes progress from condition 3 do not have time to set upcircuit 4.

Before circuit 4 can be set up, the second of the five clearing pulsesis received, setting up the tubes electronically for the clearingoperation, but clearing relay cannot yet operate because it has not hadtime. Consequently the tubes will additional impulses.

not be responsive to any Therefore, the receipt of impulse No. 3 doesnothing, receipt of No. 4 does nothing. and receipt of No. 5 doesnothing. Armature a has not yet opened. By the time it catches up withthe opens, thereby deionizing all of the tubes and restoring theapparatus to initial condition, the impulses have stopped coming in andthere are no impulses for the tubes to count.

Thus, if circuit No. 2 is closed and it is desired to open it and closeNo. 4, the operator would not send two more pulses only, but would sendthe clearing signal (five pulses) followed by the new signal (fourpulses).

It has been found in actual use of the circuit that it will respond topulses of the order of microseconds duration or less sent at a pulserate of as high as 1,000 per second, at a rate of about ten groups persecond.

For the purpose of completing the disclosure, but not by way oflimitation, the following table of values is given:

Resistances in ohms unless otherwise stated ll 50K l3 meg 2.2 l5 820 I66800 ll 820 I8 10K [911- 2200 2| 56K 23 meg 2.2 24 2200 25 3300 26 10K21 3900 281'.. 10K 8 50K 9 25K 3| 56K 33 meg 2.2 34 220K 35 6800 38 82K31-, 10K 4| 40K While I have shown and described certain preferredembodiments of my invention, it will be understoodthat modifications andchanges may be made without departing from the spirit and scope thereof,as will be clear to those skilled in the art.

to condition 4, but the relays 7. I claim: 1. In pulse controlledapparatus, in combination, a series of ionizable thermionic tubes, eachcomprising a cathode, an anode, and a control electrode, anelectro-magnetic relay for each.

or said tubes operated by the space current in the respective tubes,said relays being incapable of operation in the time in which said tubesionize or deionize, a plurality of control circuits exceeding'the numberof said tubes, said circuits beingmade by operation of individual relaysand combinations of relays, means for impressing control pulses on allof said tubes, and means for causing said tubes to operate successivelyand in successive combinations in response to impressed pulses saidapparatus operating either as a sequence or as an integral controller,depending on the duration and spacing'oi received pulses.

2. In pulse controlled apparatus, in combination, a series of ionizablethermionic tubes, each.

comprising a cathode, an anode, and a control electrode, anelectro-magnetic relay for each of said tubes operated by the spacecurrent in the respective tubes, said relays being incapable ofoperation in the time in'which said tubes ionize or deionize a pluralityof control circuits exceeding the number of said tubes, said circuitsbeing made by operation of individual relays and combinations oi relays,means for impressing control pulses on all of said tubes, and means forcausing said tubes to operate successively and in successivecombinations in response to impressed pulses, said last mentioned meansincluding means having a longer operating time than said tubes forcausing the last operation of the combination to clear the apparatus forinitial operation said apparatus operating either as a sequence or as anintegral controller, depending on the duration and spacing of receivedpulses.

3. In pulse controlled apparatus, in combination, a series of ionizablethermionic tubes, each comprising a cathode, an anode, and a controlelectrode, an electro-magnetic relay for each of said tubes operated bythe space current in the respective tubes, said relays being incapableof 4 operation in the time in which said tubes ionize or deionize aplurality of control'circuits exceeding the number of said tubes, saidcircuits being made by operation of individual relays and combinationsof relays, means for impressing control pulses on all of said tubes, andmeans for causing said tubes to operate successively and in successivecombinations in response to impressed pulses, said last mentioned meansincluding means having an operating time longer than said tubes forcausing the last operation of the combination to open the space currentcircuit of each of said tubes to restore the apparatus to initial.

condition, said apparatus operating either as a sequence or as anintegral controller, depending on the duration of spacing of receivedpulses.

4. In pulse controlled apparatus, in combination, a-series of ionizablethermionic tubes, each comprising a cathode, an anode, and a controlelectrode, an electro-magnetic relay for each of said tubes operated bysaid space current in the respective tubes, said relays being incapableof operation in the time in which said tubes ionize or deionize, aplurality of control circuits exceeding the number of said tubes, saidcircuits being made by operation of individual relays and combinationsoi relays, means for impressing control pulses on all oi said tubes,means for normally maintaining a negative bias on one control electrodeor each oi! said tubes other than the first to prevent firing of saidtubes, and connections between each of said tubes other than the first,and the preceding tube, such that as each tube fires it reduces thenegative bias on the control electrode of the succeeding tube and meanshaving an operating time longer than said tubes for restoring theapparatus to initial condition in response to a predetermined signal,said apparatus operating either as a sequence or as an integralcontroller, depending. on the duration and spacing of received pulses.

5. In pulse controlled apparatus, in combination, a series or ionizablethermionic tubes, each comprising a cathode, an anode, and a controlelectrode, an electro-mechanical relay for each of said tubes operatedby the space current in the respective tubes, a plurality of controlcircuits exceeding the number of saidtubes, said circuits being made byoperation of individual relays and combinations or relays, means forimpressing control pulses on all oi! said tubes, means -for causing saidtubes to operate successively predetermined clearing signal irrespectiveoi thecondition of said apparatus when said clearing signal is received.

6. In pulse controlled apparatus, in combination, a series of ionizablethermionic tubes, each comprising a cathode, an anode, and a controlelectrode, an electro-mechanical relay for each of said tubes operatedby the space current inthe respective tubes, a plurality of controlcircuits exceeding the number of said tubes, said circuits being made byoperation of individual relays and combinations of relays, means forimpressing control pulses on'all of said tubes, means for causing saidtubes to operate successively and in successive combinations in responseto impressed pulses, said last mentioned means including an Ielectro-m'echanical relay responsive to a predetermined clearing signaland independent of the condition of the apparatus when the said clearingsignal is received for opening the space current circuit of each of saidtubes to restore the apparatus to initial condition, the operation timeof said relays being greater than the time required by said tubes toionize.

DANIEL GIANSANTE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

